Delay technique in e-mail filtering system

This application is a continuation of U.S. application Ser. No. 10/915,216, filed Aug. 9, 2004, which is itself a continuation of U.S. application Ser. No. 10/667,488, filed Sep. 22, 2003, now abandoned.

1. Field of the Invention

The present invention relates to communication systems, and more particularly to electronic message delivery.

2. Description of the Related Art

Receiving unwanted electronic messages, such as e-mail messages, wastes time and valuable resources. Electronic message communication has become a prevalent, and perhaps preferred, method of communication in today\'s world. Such communication is apparent in most aspects of daily life including workplace, home, and travel. At the workplace, the messages may arrive from clients, partners, customers, or other employees. Additionally, unwanted messages commonly known as “SPAM” are received by users. The circumstances are similar for the home user where both wanted and unwanted SPAM messages are received. Reviewing the SPAM messages consumes time, which may be highly valuable in the case of workplace time, and may also undermine the user\'s capacity to receive other, desirable, messages. In addition, when the flow of unwanted messages is large, it also impact the computer infrastructure (bandwidth, storage, CPU). Additionally, the email infrastructure has become a very common way to spread viruses and the trend has been that some of the most recent viruses spread very rapidly and there is often a window of time of several hours during which anti-virus products are not capable of detecting a new virus yet. Accordingly, there is a need for a method for controlling and reducing the number of harmful data, such as SPAM messages or virus-carrying messages, received by users associated with a store and forward protocol relay.

Accordingly, the present invention provides a store and forward relay that delays the delivery of data to user stations or the next relay in the transmission path. The delivery delay is triggered by reference to a delay policy of the store and forward relay. The delayed data packages are maintained in a quarantine storage area until a policy is applied to the data packages. The application of the policy to the delayed data packages is determined by reference to a delay processing module. A data package may be returned to the quarantine area after application of the policy. The delaying and applying a policy to the package may be repeated several times until either the data package is properly characterized or it is determined that further delaying the data package is not acceptable.

In one embodiment, the invention provides a method for controlling transmission of messages in a data communication network where each message is associated with a message source. The method includes providing a store and forward relay, which is associated with a plurality of recipients receiving messages. The relay receives a message intended for a recipient associated with the e-mail network. the relay applies a first filtering policy to the message. The relay then delays the delivery of the message in response to at least one predetermined result of applying the first filtering policy. The relay applies a second filtering policy to the message after a delay period. Finally, the relay delivers the message in response to at least one predetermined result of applying the second filtering policy.